1. Field of the Invention
This invention relates to refrigerating and/or freezing equipment and more particularly, though not solely, to equipment used to collect and evaporate surplus (defrost) liquid water produced by refrigeration equipment.
2. Description of the Prior Art
During the operation of refrigerating or freezing equipment (which henceforth will be generally referred to as refrigeration equipment), water (present in the form of water vapour in the air within the various compartments of the refrigeration equipment) condenses on the refrigeration equipment's cooling surfaces and is then cooled to produce ice. Eventually, the amount of ice built up on the cooling surfaces (evaporator) becomes a hindrance to the efficient operation of the cooling mechanism and may also cause structural damage due to the expansion (upon cooling) of condensed water which may have found its way into narrow gaps in the refrigeration equipment.
In order to remove ice and liquid water from the refrigeration equipment, most refrigerators and freezers regularly, or upon instruction (for example from an operator or under software control) carry out a defrost cycle in which heat is introduced into the refrigeration equipment (from a heater element or the like) in order to melt any built up ice. The liquid thus formed (defrost liquid) may then be directed out of the various compartments of the refrigeration equipment under the influence of gravity through a system of channels and passageways. In many cases, the defrost liquid is fed to a container to be emptied by a user or alternatively, the container may be positioned adjacent to the compressor of the refrigeration equipment so that the heat produced during the normal operation of the compressor may be beneficially utilised to evaporate the defrost liquid away. In the latter embodiment, the container is called an "evaporation tray" and is usually positioned atop the compressor to take full advantage of heat conducted through the compressor housing and convected heat carried by air passing around and over the compressor.
Conventional evaporation trays are made from a solid, inflexible plastics or metal material in the shape of a comparatively short (vertically) rectangular, open topped box. The base of the tray has, in recent times, been shaped so as to accommodate the top of the compressor in an efficient heat transfer relationship. Many compressor housings have a convex shaped top and the base of the matching evaporation trays are therefore formed with a curved section to allow the tray to contact the top of the compressor over a surface area which is as large as possible. In this way heat transfer and thus the volume of water which may be evaporated from the evaporation tray in a given time are maximised. However, the thickness of the evaporation tray reduces the amount of heat transferred from the compressor as do any air gaps formed when the evaporation tray is not in contact with the compressor housing. It has been found that the volume of water arriving at the evaporation tray varies considerably with time. During defrosting, a large volume of water arrives at the evaporation tray in a short period of time whereas during the normal operation of the refrigeration device, where the only cause of defrosting is the introduction of warm air to the compartments by the opening of a door, very little water arrives at the evaporation tray over a significantly longer period of time. In addition, when the refrigeration equipment is installed in regions of high ambient humidity, the evaporation rate from existing evaporation trays is often less than the rate of defrost liquid production. Accordingly, the evaporation tray has been required to accommodate (and attempt to evaporate as quickly as possible) a large influx of water without overflowing.
One attempt to resolve this problem has been by the introduction of a secondary "overflow" evaporation tray which receives the overflow from the main tray atop the compressor. This setup is however undesirable as it requires extra hardware and is therefore costly. Furthermore it would be desirable to be able to produce only one model of evaporator tray in a variety of refrigeration equipment models. This is presently not possible while maintaining the required heat transfer. It would also be beneficial if the evaporation tray could be reduced in volume as this could mean a reduction in the overall volume of the refrigeration equipment set aside for the compressor could be achieved, allowing an increase in the useable cooling space within the refrigeration equipment. However, presently available evaporation trays are unable to quickly evaporate the defrost water and accordingly, must be capable of storing a large quantity of defrost water so that it may be evaporated over a comparatively longer period of time. An easily removable evaporation tray would also be desirable as it would allow the user to simply remove the tray for regular cleaning.
It is, therefore, an object of the present invention to provide liquid collection and evaporation means for refrigeration equipment which goes some way towards overcoming the above disadvantages or which will at least provide the industry with a useful choice.
Accordingly, in one aspect, the invention consists in liquid collection and evaporation means for refrigeration equipment adapted to collect liquid produced during the operation of said refrigeration equipment, said refrigeration equipment having a heat producing means with a heated surface, said liquid collection and evaporation means comprising:
substantially rigid frame means adapted for positioning adjacent said heated surface and forming a peripheral support which defines at least the extremities of a substantially horizontal opening, and PA1 flexible tray forming membrane means suspended at its periphery from said peripheral support, enclosing the space below said opening, said membrane assuming a tray shape capable of holding at least a predetermined volume of said liquid and adapted to contact and deform to the shape of said heated surface to enable heat to pass there through to evaporate said liquid. PA1 a refrigeration system which, when operational extracts heat from within said refrigeration equipment, including a heat producing means which upon energisation produces heat, said heat producing means having a surface which is heated by at least some of said heat produced by said heat producing means, PA1 cabinet means containing at least one cooling compartment which is cooled due to the operation of said refrigeration system, said at least one cooling compartment on occasion producing a liquid flow due to the operation of said refrigeration system, PA1 liquid channelling means which collect said liquid flow from within said at least one compartment and direct said liquid flow outside said at least one cooling compartment, said liquid channeling means having an outlet outside said compartment through which collected said liquid flow is directed PA1 substantially rigid frame means adapted positioned adjacent said heated surface of said heat producing means, and PA1 flexible tray forming membrane means suspended at its periphery from said peripheral support, enclosing the space below said opening, said membrane assuming a tray shape capable of holding at least a predetermined volume of said liquid and adapted to contact and deform to the shape of said heated surface to enable heat to pass there through to evaporate said liquid.
In a second aspect, the invention consists in refrigeration equipment comprising: